Rotation angle sensor having single wire windings and method for winding a rotation angle sensor

Abstract

A rotation angle sensor and a method of winding a rotation angle sensor involve a single electrical wire that is wound from a rotor transformer to a magnetic rotor. The magnetic rotor is axially spaced on a shaft from the rotor transformer. A notch is formed in a wall of a bobbin of the rotor transformer to permit the wire to pass from the rotor transformer to the magnetic rotor. The ends of the single wire are electrically connected together at a junction, and the junction is fixed to the rotor transformer with resin.

1. A rotation angle sensor comprising:
 a shaft; 
 a rotor transformer located on the shaft, which includes a coil bobbin, wherein a notch is formed in a side wall of the coil bobbin; 
 a magnetic rotor located on the rotation shaft, wherein the magnetic rotor is axially spaced from the rotor transformer; 
 a continuous electric wire, which forms a rotor transformer winding and a magnetic rotor winding, wherein the continuous electric wire is continuously coiled on the coil bobbin of the rotor transformer to form a rotor transformer winding, and the electric wire is continuously coiled on the magnetic rotor to form a magnetic rotor winding, and the wire passes from the rotor transformer to the magnetic rotor through the notch, and a first end and a second end of the wire are electrically connected together. 
 
   
   
     2. The rotation angle sensor of  claim 1 , wherein the magnetic rotor includes a core, which is a lamination of metal plates. 
   
   
     3. The rotation angle sensor of  claim 1 , wherein the second end of the electric wire passes from the magnetic rotor to the rotor transformer and is electrically connected to the first end of the electric wire, and the first and second ends of the electric wire are fixed to the rotor transformer winding with resin. 
   
   
     4. The rotation angle sensor of  claim 3 , wherein the magnetic rotor includes a core, which is a lamination of metal plates. 
   
   
     5. The rotation angle sensor of  claim 2  wherein the laminated core of the magnetic rotor includes a plurality of projections, which form magnetic poles, and the wire is coiled around each of the projections. 
   
   
     6. The rotation angle sensor of  claim 1 , wherein the coil bobbin of the rotor transformer has ring-shaped grooves extending at a right angle to the rotation shaft, and the electric wire is continuously coiled in the grooves. 
   
   
     7. The rotation angle sensor of  claim 1 , wherein a wall that defines the notch is coated with resin to reduce friction between the wall defining the notch and the electric wire. 
   
   
     8. A method of winding an electric wire on a rotor transformer and a magnetic rotor of a rotation angle sensor, wherein the rotor transformer and the magnetic rotor are axially spaced apart on a shaft, wherein the method comprises:
 winding a single electric wire around the rotor transformer; 
 feeding the electric wire through a notch formed in a side wall of a bobbin on the rotary transformer; 
 winding the wire around a plurality of projections of the magnetic rotor; and 
 electrically connecting a second end of the wire to a first end of the wire. 
 
   
   
     9. The method of  claim 8  including passing the wire from the magnetic rotor to the rotary transformer through the notch after winding the wire around the projections of the magnetic rotor and before connecting the first end to the second end. 
   
   
     10. The method of  claim 8 , wherein the method further includes attaching a junction at which the first end and the second end are connected to the rotor transformer with resin.